28039902 has 64 divisors (see below), whose sum is σ = 65919744. Its totient is φ = 7856640.

The previous prime is 28039889. The next prime is 28039909. The reversal of 28039902 is 20993082.

It is a super-2 number, since 2×28039902² = 1572472208339208, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28039909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 74988 + ... + 75360.

It is an arithmetic number, because the mean of its divisors is an integer number (1029996).

Almost surely, 2^28039902 is an apocalyptic number.

28039902 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 28039902, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32959872).

28039902 is an abundant number, since it is smaller than the sum of its proper divisors (37879842).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28039902 is a wasteful number, since it uses less digits than its factorization.

28039902 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 473.

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 28039902 is about 5295.2716644191. The cubic root of 28039902 is about 303.8030739280.

The spelling of 28039902 in words is "twenty-eight million, thirty-nine thousand, nine hundred two".